Identification of catalytically active species and reaction pathway in catalytic solid (catalyst)-solid (reactant) reactions is a nontrivial task as exemplified in diesel soot oxidation (combustion), the technology for control of diesel particulate emissions. A physical contact between catalytically active species and solid soot is usually deemed necessary. Herein, thermally-stable hollandite-type α-MnO₂ (K_xMn₈O₁₆) nanorod catalysts have been synthesized with one-dimensional tunnel structures partially filled with relatively mobile K cations. These tunnel-confined quasi free K cations are revealed to be responsible for the catalytic soot oxidation activity, proving that physical contact between soot and K cations is unnecessary for solid-solid reaction. A novel catalyst, K_yTi₈O₁₆ has been successfully designed to boost the catalytic activity in TiO₂ toward soot oxidation by engineering a K-contained hollandite-type isostructure.

识别催化固体（催化剂）-固体（反应物）反应中的催化活性物质和反应途径是一项艰巨的任务，例如柴油机烟尘氧化（燃烧）技术即控制柴油机微粒排放的技术。通常认为催化活性物质和固体烟灰之间需要物理接触。在本文中，热稳定的硬锰矿型α-MnO的₂（K _X的Mn ₈ Ô ₁₆）纳米棒催化剂已被合成为一维通道结构，部分填充了相对可移动的K阳离子。这些隧道约束的准游离K阳离子显示出催化的烟灰氧化活性，证明了烟灰和K阳离子之间的物理接触对于固-固反应是不必要的。已成功设计出一种新型催化剂K _y Ti ₈ O ₁₆，以通过设计一种含K的堇青石型同质结构来提高TiO _2中烟灰氧化的催化活性。